This application seeks support for a meeting on particle accelerators in radiation therapy, to be held at the Lawrence Berkeley Laboratory in Berkeley, California in September, 1976. This will be the second meeting in a series which started in October of 1972. The first conference (Part I) was held in Los Alamos Scientific Laboratory and over 300 scientists attended. The purpose of this meeting is to once again bring together those who are working in the field of particle therapy for an update on the state of the art in the use of accelerated particles in medicine. Much has been accomplished in the period since the first meeting, and these accomplishments should be documented to the scientific community.